Mercury and other vapor electric lamp.



H. A. KENT & H. G. LAOELL.

MERCURY AND OTHER VAPOR ELECTRIC LAMP.

APPLICATION FILED DEC. 27, 1911.

Patented Mar. 4, 1913.

3 M we Ea 1m E m6 YD M N EMM HH R m 5 Ma wfi/z UNITEDSTATES PATENToFFIoE.

. HENRY ANDREW KENT, BOUNDS GREEN, AND HAROLD GEORGE LACELL, OF IFINCHLEY, ENGLAND, LASSIGNORS TO THE SILICA SYNDICATE LIMI ITED, OF ILONDON, ENGLAND.

.MERCURY AND. OTHER VAPOR ELECTRIC LAMP.

Specification of Letters Patent.

Patented Mar. 4, 1913.

To all whom it may concern: I

Be it known that we, HENRY ANDREW KENT and HAROLD GEORGE LAOELL, bothsubjects of the King of Great Britain and Ireland, and respectivelyresidents of The Poplars, Maidstone Road, Bounds Green, county ofMiddlesex, England, and Ardoch, Nether street, Finchley, in said county,have invented new and useful Improvements in Mercury and other VaporElectric Lamps, of which the following is a specification.

This invention relates to mercury, and other vapor, electric lamps ofthe general character described in the specifications of Letters PatentsNos. 923124 and 939708 granted to us, and the objects'of the presentinvention are to provide such. lamps with eflicient means for startingthe lamp, for preventing impediment to the working of the lamp by'smallquantities of air, or gas, remaining in the lamp after it has beencharged with mercury, or other vaporizable matter, or entering the lampfrom the ends and obstructing the passages to and from the cups and forefiiciently closing the lamp containing the mercury, or othervaporizable matter, for transport with convenience and safe y.

We will, for the purposes of description, presume that mercury is thevaporlzable matter used in the lamp.

The means for starting the lamp are such that quick and forciblegeneration of vapor is caused to take place to start the arc in theilluminating portion of the lamp by breaking the column of mercurytherein. For this purpose there is, in communication with theilluminating portion of the lamp, a receptacle containing mercury and incommunication with the said receptacle, by means of a contractedpassage, or nozzle, is another receptacle also containing mercury and anelectric heater is so applied that the mercury in the first receptacleis first vaporized and then this receptacle becomes heated to a veryhigh temperature, and afterward the mercury in the second rece taclebecomes heated and passes into t e first receptacle, the intense heat ofwhich rapidly converts the mercury into such high tension vapor that, byit, the column of mercury in the ill-uminating portion of the lamp isbroken and the are rapidly formed.

A device for the aforesaid purpose is illustrated in section in theaccompanying drawing, showing a lamp in section.

The said device consists of a tube 1, communicating with theilluminating portion 2, of the lamp, the said tube 1, being closed atits lower end and provided, at a suitable distance above that end, witha division, or partition, 3, and upwardly projecting nozzl e 4 the partsabove and below the said division, or partition, 3 constituting,respectively, the aforesaid first and second receptacles which cause thearc to be struck rapidly as hereinbefore explained. The said receptaclesare surrounded by an electric heater, the connections with the electricsupply of the lamp being so made that the current at first passesthrough the heater and, after the arc has been started, the heater isshort-circuited by the rise of mer cury in the lamp, for example asexplained in the specification of the aforesaid Letters Patent No.939708.

When the current is switched on to start the present lamp it flowsthrough the re sistance wire and heats the tube 1 to such degree thatthe temperature of the mercury is raised to the boiling point. Thehottest portion of the mercury in the tube is located substantially ator a trifle above the septum 3. The result is that the mercury lyingjust above the septum is vaporized and the expansion of thls vaporforces the column above it in the tube out into the lamp leaving thetube below the septum momentarily full of liquid mercury. A few secondsnow suffice to bring the portion of the tube above the septum and itscontained vapor to red heat. This state having been obtained the liquidmercury below the septum has become sufliciently heated to raise it tothe boiling temperature and the production of vapor therein parts thiscolumn below the septum at about its mid-point and forces liquid mercurythrough the noz-' zle 4 into the red hot portion of the tube above theseptum- 3, with the result that vapor is produced in the upper portionof wire is cut out, as described in the Patent 939,708 above mentioned.

In the drawing the portion 2 is shown contracted but of course if thegeneral bore of the lamp tube be suitable for the portion 2 suchcontraction will not be required.

For preventing impediment to the working of the lamp by small quantitiesof air, or gas, which may be in the lamp, the cups 5, at the top intowhich the mercury rises through a contracted passage, are each formedwith a funnel-shaped bottom 6, inside the upper ends of the lamp, thesaid funnel-shaped bottoms having a small orifice 7, for the passage ofmercury to and from the cups, the spaces 8, surrounding the saidfunnel-shaped bottoms 6, forming receptacles for the aforesaid air, orgas. For enabling the lamp containing the mercury to be safelytransported, each of the said cups 5, is provided with a closing device,such as a valve, or stopper, by which an immovable column of mercury canbe maintained between the orifices 7, at the funnel shaped bottoms 6, ofthe cups 5, until the lamp is installed for use. These closing devicesmay each consist, for example, as illustrated in the drawing, of a ball9, of resilient material carried by a stem 10, screwed through a stopper11, fixed 'in the upper end of each cup 5, and provided with a milledhead 12. If it be desired to limit the pressure in the lamp to that ofthe atmosphere, or a few centimeters of mercury above that of theatmosphere, then each of the stoppers 11 is provided with a passage 13,open to the atmosphere when. the .lamp is at work, which passage 13,when the lamp is to be transported, can be closed by any suitable means,such as by screwing down a nut 14, on the valve stem 10, so as to closethe said air passage .13, preferably with the intervention of a washer15, situated between the said nut 14, and the top of the stopper 11.When the lamp is to be used, the said closing devices are screwed. awayfrom their seats and if there be air passages through the stoppers, themeans which effect their closure can be removed, or operated, andcommunication with the atmosphere be established above the mercury whensuch communication, is required.

It is to be understood that this invention is not limited to the precisedetails shown posed in any desired position relatively to the otherportions of the lamp.

lVhat we claim is 1. In a vapor electric lam of the character described,a lamp bo y adapted to contain a vaporizable liquid, and a startingdevice therefor comprising communicating receptacles for the vaporizableliquid one of which is open to the lamp body, in combination with meansfor heating said receptacles to vaporize the liquid in the one which isopen to the lamp, in f dvance of the other, for the purpose described.

2. In a vapor electric lamp, a starting device comprising a chambercommunicating with the lamp body, a second chamber communicating withthe first, and heating means to expel the vaporizable liquid in thefirst chamber andthen introduce into the thus heated chamber vaporizableliquid from the second chamber to produce the rapid vaporization of saidliquid from the second chamber, for the purpose described.

3. In a vapor electric lamp, a starting de- 4. In a vapor electric lamp,a starting device comprising a tube open to the lamp body, an aperturedseptum dividing said tube into communicating chambers, and a resistancewinding on the tube arranged to vaporize the liquid in the chamber opento the lamp body in advance of that 1n the chamber beyond the septum,for the purpose described.

5. In a vapor electric lamp, a starting device comprising a tube open tothe lamp body, a septum with nozzle dividing said tube intocommunicating chambers, and a resistance winding on the tube' arrangedto vaporize the liquid in the chamber open to the lamp body in advanceof that in the chamber beyond the septum, for the purpose described.

6. In a vapor electric lamp, a hollow body portion and cups at each endthereof, the bottoms of said cups being funnel-shaped with centralaperture, and the body portion of the lamp being enlarged at thejuncture with said cups to form a chamber surrounding the funnel-shapedbottom of the cups,

of the lamp being enlarged at the juncture names to this specificationin the presence of with said cups to form a chamber surroundtwosubscribing witnesses.

ing the funnel-shaped bottom of the cups, HENRY ANDREW KENT.

together with plug closures for the aper- HAROLD GEORGE LACELL. 5 turesin said funnel-shaped bottoms of the Witnesses:

cups, for the purpose described. Geo. T. FULLER,

In testimony whereof we have signed our CHAS. W. CROCKER.

